Polyvinyl chloride plasticized with adducts of alkylated aromatic hydrocarbons and fumarate esters



United States Patent POLYVINYL CEQLGRIDE PLASTICIZED WITH AD- DUCTS 0FALKYLATED AROMATIC HYDRO- CAERBQNS AND FUMARA'I'E ESTERS Joachim Danni,Basel, Switzerland, assignor to Monsanto Chemical Company, St. Louis,Mo., a corporation of Delaware No Drawing. Original application Nov. 23,1954, Ser. No. 470,798, new Patent No. 2,897,230, dated July 28, 1959.Divided and this application Feb. 4, 1959, Ser. No. 751,030

3 Claims. (Cl. mill-31.8)

This invention relates to derivatives of a, 8-unsaturated olefinic acidsand more particularly provides a new and valuable class ofpolycarboxylates, a process of producing the same, and vinyl chloridepolymers plasticized with the new compounds.

An object of the invention is the provision of new and usefulpolycarboaylates. Another object of the invention is the preparation ofuseful addition products of certain aliphatic a, 3-unsaturated olefinicdicarboxylic acid esters and hydrocarbons containing an aromaticnucleus. A further object or" the invention is to provide for thesynthetic resins and plastics, rubber, and textile industries a newclass of stable, viscous compounds of high carboxylate content.

These and other objects hereinafter disclosed are provided by thefollowing invention wherein there are prepared liquid mixtures ofpolycarboxylates by the addition of certain alkylated aromatichydrocarbons with certain esters of aliphatic cc,fi-Olfii1i0dicarboxylic acids. The reaction is one of simple addition in which onemole of the alkylated aromatic compound adds to from 2 to 20 moles ofthe ester, substantially according to the scheme:

3: x'L-noooor' in wmch R is a hydrocarbon radical tree of non-benzenoidunsaturation having from 6 to 18 carbon atoms and containing an aromaticnucleus attached through one carbon atom thereof to the remainder of themolecule of which said R forms a part, X is selected from the classconsisting of hydrogen and the methyl and ethyl radicals, X is abranched-chain alkyl radical when X is hydrogen and is selected from theclass consisting of straight-chain and branchedchain alkyl radicals whenX is one of said methyl and ethyl radicals and the total number ofcarbon atoms in the sum of X and X is from 2 to 17, and n is an integerof from 2 to 20.

One class of alkylated aromatic hydrocarbons having the above formulaand useful for the present purpose comprises alkylated benzenes havingone hydrogen atom attached to the c-carbon atom of a branched-chainalkyl group thereof and containing a total of from 9 to 27 carbon atomsin the molecule. Examples of such presently useful alk l benzenes areisopropylbenzene, 2-, 3- and 4-diisopropylbenzene,1,3,5-triisopropylbenzene, 4- ethylcumene, sec-butylbenzene,isoamylbenzene, (Z-ethylhexyl)benzene, 2-isopropyl-n-octylbenzene,isododecylbenzene, branched-chain octadecylbenzene,3-sec-butyl-nhexadecylbenzene, etc.

Another class of alkylated aromatic hydrocarbons which "ice are used inpreparing the present polycarboxylates are alkylated naphthalenes havingone hydrogen atom attached to the a-carbon atom of a branched-chainalkyl group thereof, e.g., 1- or Z-isopropylnaphthalene,1,2-diisopropylnaphthalene, l-secbutylnaphthalene,l-isooctylnaphthalene, 2-isododecylnaphthalene, etc.

Still another class of presently useful alkylated aromatic hydrocarbonsincludes alkylated biphenyls in which the m-carbon atom of abranched-chain alkyl group thereof carries one hydrogen atom, e.g., 2-,3- or 4-isopropylhiphenyl, 4,4-diisopropylor di-sec-butylbiphenyl,4-tertdodecyl 4 isopropylbiphenyl, 2-isooctyl-4-n-propylbiphenyl,4-isopropyl-4'-methylbiphenyl, etc.

Alicyl or alkoxyalkyl esters of fumaric acid which may be employed inpreparing the present adducts are the simple or mixed alkyl fumaratessuch as methyl, ethyl, npropyl, isopropyl, butyl, isoamyl, n-hexyl,n-heptyl, noctyl or Z-ethylheayl fumarate, ethyl methyl fumarate, ethyln-hexyl fumarate, isopropyl-n-octyl fumarate, etc. The simplealkoxyalkyl fumarates or mixed fumarates in which the alcohol portionsof the ester are derived from two different alkoxyalkanols or from onemole of an alkoxyalkanol and one mole of an alkanol are likewise useful.Examples of such alkoxyalkyl fumarates are his- (2-ethoxyethyl)turnarate, bis(3-butoxypropyl) fumarate, bis(4-methoxybutyl) fumarate,ethyl Z-ethoxyethyl fumarate, butyl 3-propoxypropyl fumarate, etc.

Reaction of the alkylated aromatic hydrocarbons with the fumaric acidesters to form addition products of high carboxylic content takes placereadily by heating the hydrocarbon with the ester in the presence orabsence of an inert diluent or solvent, ordinarily at super-atmosphericpressure. When operating at an atmospheric pressure, temperatures offrom, say, ZOO-300 C. and preferably of from 240-290 C. are used. Thenumber of carboalkoxy groups present in the liquid adduct depends uponthe nature of the fumarate, the alkylated aromatic hydrocarbon and uponthe reaction conditions employed. Generally, operation within the hightemperature ranges, i.e., temperatures of above, say, 200 C., and belowthe decomposition point of any of the reactants, leads to production ofadducts containing a greater number of carboalkoxy groups than arepresent in adducts obtained from the same hydrocarbon and the same esterat the lower temperatures. The number of carboaltoxy groups present inthe adduct also depends upon the individual tumarate employed. Usuallythe lower alkyl fumarates are more reactive than either the higher alkylfuniarates or the higher alkoxyalkyl fumarates. In view of the efi'ectof the reaction conditions and nature of the fumarate upon the extent towhich the furnarate participates in the reaction, it is recommended thatfor each initial run there he experimentally determined the operatingconditions to be observed for obtaining an alkyiated aromatichydrocarbon-fumarate adduct containing the desired number of carboalkoxyradicals.

The quantity of furnarate present in the adduct will also depend uponits availability in the reaction mixture. Obviously for the formation ofadducts in which one mole of the hydrocarbon has added to an average of,say, 15 moles of the fumarate, it is necessary to provide in the initialreaction mixture a quantity of fumarate which is substantially in excessof that required for the preparation of an adduct in which one mole ofthe hydrocarbon is added to an average of, say, only 5 moles of theester. Hence, in preparing the present adducts, the quantity of fumaratefor obtaining a desired adduct should be present in the initial reactionmixture in the calculated quantities.

Since the alkyl or alkoxyalkyl fumarates are generally miscible withmost of the presently useful hydrocarbons under the reaction conditionsused, no extraneous solvent or diluent need generally be employed. Forsuccessful reaction, a diluent may or may not be present. 'When workingwith the lower boiling fumarates and/or with the lower boiling alkylatedaromatic hydrocarbons, it is advantageous to operate atsuper-atmospheric pressures.

In practice, the hydrocarbon and the ester are mixed in a reactionvessel in proportions required for an adduct of a desired carboalkoxycontent and'the mixture is heated, say, at the refluxing temperaturethereof, for a time, of, say, a few hours to several days, or until thereaction mixture no longer evidences a change in refractive-index uponcontinued heating. The product is generally a viscous liquid whichcomprises a mixture of adducts of varying carboalkoxy content andunreacted initial reactants.

Any unreacted material may be readily recovered, e.g., by distillation.

The present adducts are stable, high-boiling viscous liquids. They maybe advantageously employed for a variety of technical uses, e.g., asintermediates for the preparation of polycarboxyliccompounds to beemployed for polyamide manufacture, as moisture-proofing agents,

lubricant adjuvants, etc;

The present fumarate adducts are particularly valuable as plasticizersfor polyvinyl chloride and copolymers of at least 70 percent byweight ofvinyl chloride and up to 30 percent by weight of an unsaturated monomercopolymerized therewith, for example, vinyl acetate, vinylidene"chloride, etc. The present adducts impart great flexibility to vinylchloride polymers at very low temperatures; they are compatible withsuch polymers and show no exudation of plasticizer even at plasticizercontent of up to 50 percent. Although the quantity of plasticizer willdepend upon the particular polymer to be plasticized and upon itsmolecular weight, it is generally found that compositions having from 5percent to 50 percent by weight of the present adducts will, in mostcases, be satisfactory for general utility. The good flexibility of theplasticized composition increases with increasing plasticizerconcentration.

' In evaluating plasticizer elnciency use is made of the followingempirical testing procedures:

COMPATABI LITY Visual inspection of the plasticized composition isemployed, incompatibility of the plasticizer with the polymer beingdemonstrated by cloudiness and exudationof the plasticizer. f

' I-LARDNESS A standard instrument made by the Shore Instrument Companyis used for this determination and expresses the hardness in units offrom 1 to 100. The hardness of a composition is judged by its resistanceto the penetration of a standard needle applied to the composition undera standard load for a standard length of time.

LOW TEMPERATURE FLEXIBILITY flexibility of the composition. This valuemay also be defined as the lower temperature limit of the plasticizedcompositions usefulness as an elastomer.

VQLATILITY WATER RESISTANCE The amount of water absorption and theamount of leaching that takes place when the plasticized composition isimmersed in distilled water for 24 hours is determined.

The invention is further illustrated, but not limited, by the followingexamples:

Example I A mixture consisting of 123 g. (0.5 mole) of isododecylbenzene (r1 1.4882) and 228 g. (1 mole) of butyl fumarate (221.4440) was refluxed (270-280 C.) for 5 hours and 10 minutes. Theinitial refractive index of the mixture was n 1.4610 and at the end ofthe refluxing period it was 1.4711. Heating of the resulting product ina nitrogen atmosphere to remove material {83.8 g.) boiling below 229C./2 mm. gave as residue 147 g. of a viscous adduct (n 1.4687) andhaving a .saponification equivalent, in two different determinations, of141.9. This valuecorresponds to the calculated sa- .ponificat ionequivalent of an adduct of one mole of the dodecylbenzene with anaverage of about 4.4 mole of butyl fumarate.

7 Example 2 A mixture consisting of 119 g. (0.5 mole) of adiisopropylbiphenyl and 228 g. (1 mole) of butyl fumarate was refluxed(270-275" C.) for 9 hours. During the refluxing period the refractiveindex of the reaction mixture rose from 1.4869 to 1.4975. Heating'of theresulting product in a nitrogen atmosphere at a pressure of from 1 to 2mm. of mercury to a temperature of 225 C. to remove low-boilingmaterials gave as residue 123g. of the viscous adduct (r1 1.4866) andanalyzing 67.42% carbonand 8.38% hydrogen, corresponding to an adduct ofone mole of the diisopropylbiphenyl and an average of about 5.5 moles ofthe'butyl fumarate. The calculated -C and H values for a molecularweight of 1435 (corre sponding to the 1:55 adduct) are C, 67.50% and H,8.85%.

Example 3 This example describes the preparation of an adduct from acommercially available p-isododecyltoluene (r1 1.4891), of which boilsat 293-305 C.

A mixture consisting of 91 g. (0.35 mole) of the p-isododecyltolueneand-208 g. (0.8 mole) of bis(2-ethoxyethyl) fumarate was heated at about270 C. for 6 hours. .During the heating period the refractive index ofthe reaction .mixture rose from n 1.4632 to 21 1.4694. Distillation ofthe resulting reaction product in a nitrogen atmosphere at a pressure of0.8 mm. of mercury to remove material boiling below 254 C. gave asresidue 128.0 g. of the viscous adduct, 21 1.4718, analyzing 57.53%carbon and 8.08% hydrogen, corresponding to an adduct in which one moleof the isododecyltoluene is combined with an average of 13 moles of thebis(2- ethoxyethyl) fumarate. The calculated values for the 1:13 adductare 57.48% C and 8.03% H.

Example 4.

i example describes the'preparation of an adduct from the dodecyltolueneof Example 3 and butyl fumarate.

A mixture consisting of 130 g. (0.5 mole) of the dodecyltoluene and 228g. (1.0 mole) of the butyl fumarate was brought to a temperature of 268C. within a period of about 30 minutes and then kept at a temperature offrom 261-270 C. for 6 hours. Fractionation of the resulting reactionmixture gave the two adducts:

I. B.P. 211-236 C./ 1-2 mm., 39 g., n 1.4686, analyzing 66.78% C, 9.43%H and (by difference) 23.79% 0. l i

II. Residue: B.P. above 236 C./ 1-2 mm., 85 g., n 1.4715, analyzing65.95%, C, 9.15% H and (by difierence) 24.90% 0.

Example 5 60 parts of polyvinyl chloride and 40 parts by weight of theadduct of Example 1 were mixed on a rolling mill to a homogeneous blend.During the milling there was observed substantially no fuming anddiscoloration. A molded sheet of the mixture was clear and transparentand substantially colorless. Testing of the molded sheet for lowtemperature flexibility, according to the testing procedure describedabove, gave a value of minus 14.5 C. Tests on the volatilitycharacteristics of the plasticized composition gave a value of 1.74percent, which showed very good retention of plasticizer and indicatedgood temperature characteristics of the composition. The plasticizedmaterial had a hardness of 77 before the volatility test and a hardnessof 78 after the volatility test. When subjected to heat at a temperatureof 325 F., for a period of 30 minutes, the clarity and color of themolded product Was substantially unchanged. Tests of the waterresistanceproperties of the plasticized material employing the testing proceduredescribed above showed a solidsloss of only 0.014 percent and an 0.597percent waterabsorption value.

Example 6 The diisopropylbiphenyl-butyl fumarate adduct of Ex ample 2was evaluated as a polyvinyl chloride plasticizer employing theprocedure described in Example 5. Testing of the molded sheet thusobtained for low temperature flexibility gave a value of minus 5.7 C.Testing of the volatility characteristics of the plasticized compositiongave a value of 1.16%. The plasticized material had a hardness of 83before the volatility test and a hardness of 84 after the volatilitytest. When subjected to heat at a temperature of 325 F., for a period of30 minutes, the clarity and color of the molded product wassubstantially unchanged. Tests of the water-resistance properties of theplasticized material employing the testing procedure described aboveshowed a solids-loss of only 0.400 percent and an 0.577 percentwater-absorption value.

Example 7 The plasticizing efliciency for polyvinyl chloride of thefraction 1 and the residue 11 of Example 4 was evaluated using theprocedure described in Example 5. With fraction I there was obtained alow temperature flexibility value of minus 21.6 C., a volatility valueof 3.77%, a soiids-loss of 0.17% and a water-absorption value of 0.83%.With the residue 11 there was obtained a low temperature flexibilityvalue of minus 4.3 C., a volatility value of 0.89%, a solids-loss of0.09% and a water-absorption value of 0.75%. When subjected to heat at atemperature of 325 F. for 30 minutes, the clarity and color of themolded products obtained from either of the adducts of Example 4 weresubstantially unchanged.

The resistance of molded test specimens of polyvinyl chlorideplasticized with 40% by weight of the residue 11 of Example 4 wasdetermined as follows:

A 2" diameter 40 mil. disc was suspended in a 50 C. oven for a 3-hourconditioning period to eliminate water, then cooled and weighed. Theconditioned sample was then immersed in 400 ml. of kerosene for a periodof 24 hours, at 27 C. The. sample was then removed from the kerosene,blotted dry and suspended in a force-draft C. oven for 4 hours. Thesample was then cooled and weighed. The percent loss in weight thusdetermined, i.e., the kerosene extraction value, was found to be 1.22%.-This shows very good kerosene resistance, that of dioctyl phthalate, acommercial plasticizer, being 82% when evaluated by the same testmethod.

Example 8 Adducts of other alkyl fumarates or of other alkoxyalkylfumarates and alkylated aromatic hydrocarbons having from 1 to 2hydrogen atoms attached to the a.- carbon of the alkyl group thereof,likewise possess very good plasticizer properties for vinyl chloridepolymers. Thus by employing 40 parts by weight of the adduct of diethylor methyl n-octyl fumarate and isopropylbenzene or cumene, with 60 partsby weight of polyvinyl chloride or with 60 parts by weight of a vinylchloride-vinyl acetate copolymer known to the trade as Vinylite, theremay be obtained clear, colorless compositions of very good flexibilityand stability.

While the above examples show only compositions in which the ratio ofplasticizer to polymer content is 40.60, this ratio being employed inorder to get comparable efliciencies, the content of ester to polyvinylchloride may be widely varied, depending upon the properties desired inthe final product. For many purposes a plasticizer content of, say, fromonly 10 percent to 20 percent is preferred. The present adducts arecompatible with polyvinyl chloride over wide ranges of concentrations,up to 50 percent of esters based on the total weight of the plasticizedcomposition yielding desirable products.

Although the invention has been described particularly with reference tothe use of the present adducts as plasticizers for polyvinyl chloride,these adducts are advantageously employed also as plasticizers forcopolymers of vinyl chloride, for example, the copolymers of vinylchloride with vinyl acetate, vinylidene chloride, etc. Preferably, suchcopolymers have a high vinyl chloride content, i.e., a vinyl chloridecontent of at least 70 percent by weight of vinyl chloride and up to 30percent by weight of the copolymerizable monomer.

The plasticized polyvinyl halide compositions of the present inventionhave good thermal stability; however, for many purposes it may beadvantageous to use known stabilizers in the plasticized compositions.Inasmuch as the present adducts are substantially unreactive with thecommercially available heat and light stabilizers which are commonlyemployed with polyvinyl chloride or copolyrners thereof, the presence ofsuch materials in the plasticized products does not impair the valuableproperties of the adducts. The present adducts are of general utility insoftening vinyl chloride polymers. They may be used as the onlyplasticizer components in a compound vinyl chloride polymer or they maybe used in conjunction with other plasticizers.

This application is a division of my copending application, Serial No.470,798, filed November 23, 1954, now Patent No. 2,897,230.

What I claim is:

1. A resinous composition comprising polyvinyl chloride plasticized withan adduct of one mole of an alkylated aromatic hydrocarbon having atotal of from 9 to 27 carbon atoms and selected from the classconsisting of alkylated benzenes, alkylated naphthalenes and alkylatedbiphenyls having one hydrogen atom attached to the acarbon atom of abranched-chain alkyl group thereof, and from 2 to 20 moles of a fumarateof the formula in which Y and Y are selected from the class consistingof alkyl and alkoxyalkyl radicals of from 1 to 8 carbon atoms; saidadduct havingrbeen formed b3 heeting the alkylated aromatic hydrocarbonwith the fumaxate at a temperature of from 200 C. to 300C.

'fiimarate, said adduct having been formed by heating theisododecylbelizene with the butyl fumarate at a. temperature of 200 C.to 300 C.

.U3. A resinous composition comprising polyvinyichloiideplastieized'with 'an adduct in which 1 mole of a diisopropy1biphenyliscombined with from 2 to 20 moles of butyl fumerate, said adduct havingbeen formed by heating the diis'opropyl biphenyl with the butyl fumarateat a temperature of 200 C. to 300 'Referenees Cited in the file of thispatent UNITED STATES PATENTS "1 2 ,665,304 Petrick Jan. '5, 1954

1. A RESINOUS COMPOSITION COMPRISING POLYVINYL CHLORIDE PLASTICIZED WITHAN ADDUCT OF ONE MOLE OF AN ALKYLATED AROMATIC HYDROCARBON HAVING ATOTAL OF FROM 9 TO 27 CARBON ATOMS AND SELECTED FROM THE CLASSCONSISTING OF ALKYLATED BENZENES, ALKYLATED NAPHTHALENES AND ALKYLATEDBIPHENYLS HAVING ONE HYDROGEN ATOM ATTACHED TO THE ACARBON ATOM OF ABRANCHED-CHAIN ALKYL GROUP THEREOF, AND FROM 2 TO 20 MOLES OF A FUMARATEOF THE FORMULA